Spring hanger



March 14, 1961 P. c. SHERBURNE SPRING HANGER 2 Sheets-Sheet 1 Filed March 9, 1959 INVENTOR. PHILIP c. SHERBURNE WMQWW ATTO R N EY March 14, 1961 P. c. SHERBURNE 2,974,914

SPRING HANGER Filed March 9, 1959 2 Sheets-Sheet 2 INVENTOR. PH I LIP C. SHERBURNE ATTORN EY United States Patent SPRING HANGER Philip C. Sherbm'ne, Rumford, R.I., assignor to Grinnell Corporation, Providence, R.I., a corporation of Delaware Filed Mar. 9, 1959, Ser. No. 798,053

4 Claims. (Cl. 248-54) This invention relates to a spring pipe hanger device of the type shown in US. Re. Patent 24,050 to Rouverol. Such spring hangers exhibit the property of exerting a constant upward force independent of the position of the supported pipe load, within a certain position range. They are hence termed constant support pipe hangers.

For a given set of hanger parameters, which will be explained later in more detail, it is known that (1) the overall length of the hanger can be reduced and (2) the amount of swing of that end of the spring which in earlier constructions swung the most can be reduced by locating the spring pivot axis between the ends of the spring rather than at one end or beyond such end. However, in so locating the spring pivot between the ends of the spring it has been the practice to provide pivoting mechanism in the form of a pair of separate but axially aligned pivotal connections located outside the spring. Thus the pivotal connections have a single axis passing through the spring. However, because a pivot pin cannot pass through the spring a yoke arrangement is required, and such a construction involves difliculties in manufacture and an increase in the frame width with a wider enclosing spring cover or frame.

By the novel construction of the present invention, the overall length of the hanger is also reduced by cating the spring pivot axis between the ends of the spring, but the use of two pivots external to the spring is avoided, the new construction having only one pin on the inside of the spring.

In the drawings:

Fig. 1 is a longitudinal cross-sectional view, partially broken, of the spring hanger of this invention.

Fig. 2 is a view taken along line 2-2 of Fig. 1.

Fig. 3 is a partial sectional view taken along line 33 of Fig. 1.

Fig. 4 is a skeletal view of portions of the hanger.

Referring now to Figs. 1 and 3 of the drawings, the numeral 10 denotes the constant support spring hanger of this invention and includes a frame 12 fashioned of heavy sheet stock, resembling an inverted channel member. Suitable reinforcing elements 14 may extend between the sides of the hanger for greater rigidity. A pin 16 passes through a lower part of the hanger and supports a bell crank lever 18. The latter includes a lever arm 20 and a spring arm 22 and may be formed of two parallel members. To one end of the frame is fastened a cylindrical spring housing 24 through a connecting disklike element 26. The element may be conveniently made by casting and is secured as by bolts to the parallel sides of the frame 12. The casting 26 has two apertures 27 at its center (see Fig. 3) between which extends an apertured integral projection 28. A pin 30 is carried by the projection at its end and passes through ears 32 of one spring end plate 34 and pivotally supports the latter about the pin.

Parallel links 36 extend through the other spring end plate 28 at one end, receiving transverse pins 39 which bear against plate 38. The links are pivotally connected 2,974,914 Patented Mar. 14, 1961 downwardly, arms 20 and 22 oscillate about pivot pin 16 and links 36 slide relative to pivot 30. Pin 38 describes an arc with these movements and link members 36 rock as they slide along pin 30, following the arcuate motion of the connection at 38. As links 36 change their inclination, plates 34 and 38 also change, retaining their parallelism. Plate 34 rocks about pin 30.

Reference now to the skeletal diagram of Fig. 4 will demonstrate the constancy of the hangers supporting force and is given here to more clearly apprize the reader of the invention. For simplicity certain parts have been designated by letters rather than numerals.

Let L denote the load; A the angle between the load arm a and the vertical; b the spring arm; a the spring deflection, being the distance between points 30 and 38; c the distance between points 16 and 30; B the angle between 11 and c; k the constant of the spring; and h the perpendicular distance from the line of action of the spring to the pivot 16.

(1) Taking moments about 16, for equilibrium,

La sin A=kdh (2) From trigonometry,

kdbc siu B d (4) Making the hanger so that A=B, the above reduces to La sin A:

where all quantities on the right are constants of the hanger, so that regardless of the value of the equal angles A and B (which value varies with lever rotation) the supporting force is the same.

It will be noted that location of the pin 30 to the right of the right spring end plate, as is the. case in some prior hangers of this type, would increase the hangers length. The position of the pin 30 to the left of the spring plate 34 in Fig. 4 allows for a shorter hanger while satisfying the above requisite constant support conditions. The pin 30 is located between the end plates 34 and 38 by virtue of the novel structural arrangement shown, particularly in Fig. 3, so that the use of two pivots outside the spring is avoided.

I claim:

1. A spring hanger including a frame having first and second portions, a lever pivoted to said first frame portion, a link secured at one end to the lever and fixed at its other end to a spring plate, a pivot on said second frame portion slidably and pivotally carrying the link, a second spring plate pivotally carried by the said pivot, a coil spring between the plates, said first frame portion being located exterior of said spring, said second frame portion extending into the interior of said spring from one end thereof, the said pivot being located between the plates, the said pivot being located between the ends of the spring and surrounded by the coils thereof.

2. A spring hanger including a frame having first and second portions, a bell crank lever pivotally secured to 3 said first frame portion and having one arm adapted to supp a p p d, a p d n h v n ne d cured to the bell crank and its other end secured to a spring end plate, a pivot pin fixed to said second frame portion and extending through a slot in the said link, a

7 second spring end plate pivoted to the pin, a coil spring extending between opposing faces of the endplates, said first frame portion being located exterior of the spring,

said second frame portion extending into the interior of said spring from one end thereof, the saidpivot pin being located between the ends of the spring and surrounded by the coils thereof.

3. A spring hanger including a U-shaped frame with parallel depending sides, a bell crank lever pivoted to frame between the said dependingwalls, one arm of the lever adapted to support a pipe load, a disc-like element secured to one end of said frame and carrying an integral projection, a pivot pin carried by said projection, a first spring end bearing plate carried by said pin, a link connected at one end to the other arm of said bell crank lever and connected at its other end to a second spring end bearing plate, said pin extending through a slot in said link, said link passing through a slot in the said first spring end bearing plate and through a slot in said disclike element, a coil spring extending between opposing faces of the said spring end bearing plates, said projection extending into the interior of said spring from one end thereof, whereby said pin is located between the said spring end bearing plates and is surrounded by the coils of said spring.

4. A spring hangerincluding a U-shaped frame with parallel despending sides, a bell crank lever pivoted to said frame between said depending walls, one arm of said lever adapted to support a pipe load, a disc-like element secured to one end of said frame and carrying an integral projection, a pivot pin carried by said projection, a first spring end bearing plate carried by said pin, a link connected at one end to the other arm of the said bell crank lever and connected at its other end to a second spring end bearing plate, said pin extending through a slot in said first spring end bearing plate and through a slot in said disc-like element, a coil spring extending between opposing faces of said spring end bearing plates, said projectionrextending into the interior of said spring from one end thereof, whereby said pin is located between said spring end bearing plates and is surrounded by the coils of said spring, distance between the said pivot pin and the connection of said link to the bell crank arm being equal to the deflection of the, spring, and the angle between the load-supporting arm of the. bell crank and the vertical being equal. to the angle between a line connecting the pivot of the bell crank to the frame with the said pin and a lineconnecting the pivot of the bell crank to the framev with the connection of the said link to the bell crank.

References Cited in the file of this patent UNITED STATES PATENTS Gould May 24, 1955 

